Nearly eight years ago, Sia Cooper couldn’t wait to become a better version of herself, thanks to her new breast implants.

“It gave me confidence,” the 29-year-old fitness trainer and Instagram model @diaryofafitmommyofficial tells The Post. But the new Sia Cooper didn’t last long.

“My health started changing for the worse.”

Believing she was suffering from “breast implant illness” — a controversial and theoretical autoimmune disease which sufferers believe is caused by silicone implants — Cooper eventually decided to have her implants removed.

Recently, in a post unrelated to her mysterious symptoms, she divulged to her inquiring Instagram followers that she had breast implants. They responded with comments about breast implant illness.

“It planted a seed in my head,” she says. “Maybe this is it.”

While the FDA does not recognize a breast implant illness (BII) diagnosis, it also states on its website that BPI cannot be entirely dismissed without “much larger and longer” studies. (It also notes a “low but increased likelihood” of being diagnosed with anaplastic large cell lymphoma (ALCL), a cancer of the immune system.)

“Breast implants are the most studied implanted medical devices in the world,” Maman tells The Post. “There has never been a scientific study in any credible medical literature showing an association” between autoimmune diseases and breast implants, “period.”

“There are women certainly that have these unexplained illnesses and then miraculously get better once the implants are removed,” he admits. “But there’s always a placebo effect.”

Cooper — who has no family history of autoimmune diseases — also decided to see the cosmetic surgeon who gave her the implants. In tune with Maman and a majority of their community, he told her there’s little evidence to support BII.

Cooper knew there was no assurance a breast “explant” would help, but, she says, “I was willing to try it.”

Less than two weeks ago, she traveled from her home in Destin, Fla., to Newport Beach, Calif., to have her implants removed by Dr. Jae Chun — a cosmetic surgeon popular in the explant community for his support of these claims. The surgery cost about $7,600 — about $2,100 more than her implants cost in 2011.

“I [can] take a deep breath for the first time,” she says, even with her mending chest. Her posture has improved, inflammation and acne are subsiding, and she’s had a boost of energy. “I have been so productive . . . My body just feels better.”

“I took my doctor for his word,” says Cooper, who wishes she’d asked more questions before getting the implants.

“I just want women to educate themselves — which is something I did not do,” she says. “Do your own research. Be your own health advocate.”

A mom of three died from a blood clot 17 days after getting a tummy tuck and boob job from a firm that advertises during hit U.K. reality show "Love Island."

Beautician Louise Harvey, 36, booked the procedures after feeling self-conscious ever since the birth of her third child.

But despite a family history of blood clots in her GP notes, she was allegedly sent home without any blood thinners. And a little over two weeks after her $14,000 operation, she collapsed at home, struggling to breathe.

She was taken to a hospital but died of a pulmonary embolism — a blood clot in one of the blood vessels in the lungs.

TEXAS WOMAN DIES FOLLOWING BOTCHED PLASTIC SURGERY IN MEXICO

Louise’s mom, Linda, 52, said the family had a history of pulmonary embolisms, but said her daughter believed the operation was safe.

“I want justice for my daughter," Linda said.

“They told her that having both procedures together would be better because she would not have to go through two lots of healing. They said she wouldn’t have to pay twice for the anesthetist and the stay in the room, even the trips down there," she added."

“Louise went to the gym and she was always self-conscious after giving birth to her 6-year-old," Linda explained.

“She had lost the weight and she just wanted to get rid of the loose skin. She was beautiful, but some people feel they want to do these things.

“When Louise told me about the double operation I was concerned because your body can only handle so much at a time.”

Louise was mom to Kayleigh, 18, Owen, 11, and Jaxon, 6. Linda is now raising the two young boys.

“Louise had no background health issues, no high blood pressure or anything. She was as fit as a flea," Linda added. “But my grandmother died of a pulmonary embolism when she was 55. My other daughter has a history of them as well. And I know for a fact Louise had no blood thinners.

“We are deeply worried she has not had the right care,’’ Linda said.

Louise is believed to have booked her “mommy makeover” after a consultation with a company called Transform in her home city of Norwich.

The family said she wanted a tummy tuck, and to have her existing breast implants enlarged and made perkier. She opted out of liposuction on her hips.

Following the operation in London in June, Louise stayed in the hospital for two nights before heading home. She proudly showed off her new breasts and was recovering “fantastically,” her family said. But she suffered a heart attack on July 3 and was taken back to the hospital, where she died two days later.

An inquest was opened earlier this week where the pulmonary embolism was confirmed as the cause of death. A full hearing will take place in Norwich in March.

NHS England chief Simon Stevens has hit out at ITV for allowing cosmetic surgery ads to be broadcast during popular shows in the U.K., such as "Love Island." He said they put young people under pressure over body image and urged broadcasters to look “very carefully at the kinds of impacts that it is having."

A source also told The Sun that “women are lured in by ads on shows such as 'Love Island' for ops that are unnecessary.

“This was a major f— up. What Transform [has] done is disgraceful.”

Transform said it has “undertaken a full internal investigation” and is offering support to Louise’s family.

This article originally appeared on The Sun. Read more content from The Sun here.